On divine command theory, courage is a good thing just in case God is essentially courageous. But if God is essentially courageous, then God was courageous even prior to creation. There were, of course, no evils prior to creation, and so genuine courage must not require evil to exist. Any courage-theodicy would then fail to identify a greater good for which God's permission of an evil was necessary; as courage is not necessary for any evil.
On the other hand, if genuine courage did necessitate evil, then God cannot be essentially courageous and thus courage cannot be a good thing. And if courage is not a good thing, God has no reason to permit evil so that we may exemplify courage. Again any courage-theodicy would fail.
And so there's a very clear problem for anyone who wishes to hold both divine command theory (versions greatest being theology would have similar problems) and hold to some theodicy. Courage was just an example, you can replace it with any possible good thing and the results should be the same. And so given divine command theory, every theodicy should be considered a failure.